Take a look at the image links. No one can predict random numbers like I can, wouldn't you say? I managed to more than quintuple the capital as it was falling to less than half its starting value, with selling short not even a choice!
http://s2.postimg.org/c8prrpct5/stock_1.png
http://postimg.org/image/9emme9amt/
http://s27.postimg.org/7aiz0lern/stock_2.png
http://postimg.org/image/imvkidngf/
http://s30.postimg.org/d9dbo4vhd/stock_3.png
http://postimg.org/image/7xyf3f9el/
http://s12.postimg.org/wyewd107h/stock_4.png
http://postimg.org/image/855ccdh6x/
Or should I say, no one can predict the future like me, when it doesn't matter. Or maybe I can in any case, I'm just subconsciously a glutton for punishment. The last time I touched the real stock market, I lost 20% of my money in less than 10 minutes. Pretty impressive, wouldn't you say? USUALLY you have to at least wait until the next DAY or at least a WHILE later to manage that level of loss. But nope. It only took me 7 minutes.
Improvements for the game:
1. make selling short a possibility. And buying on margin for that matter. I know why you didn't. You didn't want to add the complication into the game of having margin calls.
2. options. Make options available. Now THAT would be fun. Call and put options. I can help you with the mathematics of it if you want.
3. make it more obvious that it's a random walk. The idiots below me commenting think it's important that more than 1 stock be available, because they don't understand what this program is doing. Throw the stupid people a bone. Also please make sure that the mathematics are done correctly. It needs to be a true random walk on a logarithmic scale. That means, if the price is 1.00, the next price a few milliseconds later should be determined by a random number with a mean of 1.00. I suggest price one timestep forward into the future is (current price)*(1-x+2*x*rand), where x is a parameter of your choice that determines the volatility, and rand is a random number generated uniform over the interval of 0 to 1. That way there won't be any way to beat the market on average. Perhaps that is what you do already. I'm suspicious that you do. But if it isn't, that's how it should be.
4. Go ahead and make more than 1 stock available maybe. It would make the display more complicated. But just to show these people that it doesn't actually make any difference. If they're smart enough to eventually get that lesson. Program various correlations between the stocks, and make the correlation matrix subject to change.
5. Put in "news releases" to accompany the changes in price. Let the "fundamentals" traders think there's something to be told from the talking heads, which make up the explanations to fit the data after the fact. You know, if by chance the stocks take a dive, a newswire will appear at the bottom of the screen that says something like "breaking news: stocks dive on bad economic report from China" or if just one takes a dive, "breaking news: XYZ corporation faces costly litigation after...." and then the explanation could be that their drug fails FDA checking if they're a pharmaceutical company, or that someone found a finger in their burgers if they're a fast food company, or that they got ahold of insider trading if they're an investment firm, or whatever, or "XYZ corporation share price down on sales less than expected". And similar stories if it's up. But make it look like something that's relevant to the future, even though it's really just a reaction to what happened already.
6. Allow limit orders. And possibly stop orders. Don't just have a big green buy button and a red sell button.
7. Allow the volatility to change. For there to be periods where it goes up and down faster. Or slower. Or not at all, when the market is closed. But not too long with that. That would be just a psychological element, it wouldn't add any utility to the simulation.
8. A pause button. Time to enter in specific orders based on the current state of things without it constantly changing super-fast.
9. Spreads and commissions. A difference between "bid" and "ask". And you also lose 5 dollars per trade. Just to make it REALLY a losing proposition. And the spread (difference between bid and ask) should be especially large with the options, if you have them.
I love the choice of music. It's PERFECT. And yes, the game is almost perfect, despite your claims to the contrary. The only one like it I've found. And it's much how I envisioned I would make it. Which is a good sign for it, ha ha.